The present invention relates to improvements in a micrometric device for finishing high precision bores and more precisely to improvements introduced on a micrometric device used for finishing high precision through and/or blind bores. The present invention may be used to improve micrometric devices such as those described in Brazilian Patent Application No. PI 9006125, filed Dec. 3, 1990, corresponding to U.S. patent application No. 07/738,918, now U.S. Pat. No. 5,222,846 the specification of which is incorporated by reference herein.